/*--------
 * Module :			multibyte.c
 *
 * Description:		Mlutibyte related additional function.
 *
 *					Create 2001-03-03 Eiji Tokuya
 *--------
 */

#include "multibyte.h"
#include <string.h>

int			multibyte_client_encoding;	/* Multibyte Client Encoding. */
int			multibyte_status;	/* Multibyte Odds and ends character. */


unsigned char *
multibyte_strchr(const unsigned char *s, unsigned char c)
{
	int			mb_st = 0,
				i = 0;

	while (!(mb_st == 0 && (s[i] == c || s[i] == 0)))
	{
		if (s[i] == 0)
			return (0);
		switch (multibyte_client_encoding)
		{
			case SJIS:
				{
					if (mb_st < 2 && s[i] > 0x80 && !(s[i] > 0x9f && s[i] < 0xe0))
						mb_st = 2;
					else if (mb_st == 2)
						mb_st = 1;
					else
						mb_st = 0;
				}
				break;

/* Chinese Big5 Support. */
			case BIG5:
				{
					if (mb_st < 2 && s[i] > 0xA0)
						mb_st = 2;
					else if (mb_st == 2)
						mb_st = 1;
					else
						mb_st = 0;
				}
				break;
			default:
				mb_st = 0;
		}
		i++;
	}
#ifdef _DEBUG
	qlog("i = %d\n", i);
#endif
	return (char *) (s + i);
}


void
multibyte_init(void)
{
	multibyte_status = 0;
}


unsigned char *
check_client_encoding(unsigned char *str)
{
	if (strstr(str, "%27SJIS%27") ||
		strstr(str, "%27Shift_JIS%27") ||
		strstr(str, "'SJIS'") ||
		strstr(str, "'sjis'") ||
		strstr(str, "'Shift_JIS'"))
	{
		multibyte_client_encoding = SJIS;
		return ("SJIS");
	}
	if (strstr(str, "%27BIG5%27") ||
		strstr(str, "%27Big5%27") ||
		strstr(str, "'BIG5'") ||
		strstr(str, "'big5'") ||
		strstr(str, "'Big5'"))
	{
		multibyte_client_encoding = BIG5;
		return ("BIG5");
	}
	return ("OTHER");
}


/*--------
 * Multibyte Status Function.
 *	Input	char
 *	Output	0	: 1 Byte Character.
 *			1	: MultibyteCharacter Last Byte.
 *			N	: MultibyteCharacter Fast or Middle Byte.
 *--------
 */
int
multibyte_char_check(unsigned char s)
{
	switch (multibyte_client_encoding)
	{
			/* Japanese Shift-JIS(CP932) Support. */
		case SJIS:
			{
				if (multibyte_status < 2 && s > 0x80 && !(s > 0x9f && s < 0xE0))
					multibyte_status = 2;
				else if (multibyte_status == 2)
					multibyte_status = 1;
				else
					multibyte_status = 0;
			}
			break;

			/* Chinese Big5(CP950) Support. */
		case BIG5:
			{
				if (multibyte_status < 2 && s > 0xA0)
					multibyte_status = 2;
				else if (multibyte_status == 2)
					multibyte_status = 1;
				else
					multibyte_status = 0;
			}
			break;
		default:
			multibyte_status = 0;
	}
#ifdef _DEBUG
	qlog("multibyte_client_encoding = %d   s = 0x%02X   multibyte_stat = %d\n", multibyte_client_encoding, s, multibyte_status);
#endif
	return (multibyte_status);
}
